1. Bacteria
For every “human” cell, there are 20 bacteria present on our body (but they are smaller)…..this accounts for ~10% of the mass that you carry around.

2. prokaryote – unicellular
organisms that lack a nucleus
cell wall
cell membrane
DNA (no nucleus)
ribosomes
cytoplasm
flagella
pili

3. The Three Domains of Life

4. Kingdom Eubacteria larger kingdom more diverse can be found
almost everywhere
E. coli

5. Kingdom Archaebacteria
can be found in harsh environments
methanogens
halophiles
thermophiles
may be ancestors of eukaryotes

6. Symbiotic Bacteria

7. Bacterial Shapes Bacillus – rod-shaped prokaryotes
Coccus – spherical-shaped prokaryotes
Spirilla – spiral and corkscrew-shaped prokaryotes

8. Lactobacillus

9. Staphylococcus epidermidis
Streptococcus pneumoniae

10. Bacterial Locomotion Don’t move at all Propelled by flagella
Spiral forward
Glide via slime-like
secretion

11. How do bacteria obtain energy?
heterotrophs – organisms that obtain energy by consuming organic molecules made by other organisms
autotrophs – organisms
that make their own
food from inorganic
molecules

12. Release of Energy
obligate aerobes – organisms that require a constant supply of oxygen in order to live
obligate anaerobes – organisms that must live in the absence of oxygen
facultative anaerobes – organisms that can survive with or without oxygen

13. Growth and Reproduction of Bacteria
Binary Fission
Conjugation

14. Extra Protection? Spore Formation…
endospore forms when a bacterium produces a thick internal wall that encloses its DNA and a portion of its cytoplasm
allows some bacteria to survive harsh conditions (heat, dryness, lack of nutrients)

15. Bacterial Growth Curve

16. Pathogenic Bacteria